1. Field of the Invention
The present invention relates to a machine for peeling a cover of a golf ball, a method of removing the cover from a core, an apparatus for removing the cover from the core and a method of manufacturing a golf ball formed of a regenerated material.
2. Description of the Related Art
A golf ball is roughly divided into a wound ball and a solid ball. The solid ball comprises a core having a single or more rubber layers and a synthetic resin cover coated over a surface of the core. If the golf ball is used repetitively, the surface of the cover is damaged and dimples are also worn. As a result, the appearance is deteriorated and a flight distance is shortened during the lifetime of the ball. In view of this, most used golf balls are wasted. In recent years, a large amount of golf balls have been wasted with an increase in production of the golf ball, which has caused problems.
Japanese Laid-Open Patent Publication No. 10-137368 (1998/137368) has disclosed a method of collecting and regenerating used balls. In this method, a cover of the used ball having a damaged surface is peeled by means of a removing apparatus. A pair of cylindrical geared rolls which are mutually arranged in a transverse direction are used for the removing apparatus. Teeth are formed in an axial direction at a predetermined pitch over the circumferential surface of the roll and the roll is rotated inwardly with the teeth engaged with each other. A ball having a convex portion formed previously on a cover is mounted between the rolls which are being rotated. Consequently, the convex portion is bitten between the rolls and is thus pulled so that the cover is removed from a core. The cover thus removed is treated again and is utilized as a covering material.
In order to interpose the convex portion by mating the teeth with each other, it is necessary to press the rolls against each other and the teeth of the rolls are damaged easily. In addition, there is a possibility that the surface of the core might be damaged by the teeth during the removal.
Since the convex portion is formed by deforming the cover, a size thereof is restricted. For this reason, when the golf ball is put on the rolls, the convex portion cannot reach a roll nip and the cover cannot be removed in some cases. If a roll diameter is decreased, a distance between a lower end of the ball put on the roll and the nip of the rolls is reduced so that the convex portion is reliably bitten between the rolls. However, the roll having a small diameter is fragile so that troubles are practically made in respect of durability.
Furthermore, it is necessary to stably form a convex portion having a uniform dimension in order to reliably bite the convex portion, which cannot be carried out readily.
In consideration of such circumstances, it is an object of the present invention to remove a cover from a core simply and reliably and to use the core or the cover for a raw material of a regenerated golf ball.
In order to achieve the object, the present invention provides a cover peeling machine in which a pair of rolls provided close to each other are mutually rotated reversely to entangle a cover of a golf ball and to peel the cover from a core,
wherein the roll is a tapered roll having a vertical angle of 20 degrees to 40 degrees.
In the cover peeling machine, the tip of the tapered roll has a small diameter. Therefore, in the case in which the golf ball is mounted close to the tip, a distance between the lower end of the ball and the nip of the roll is reduced. Accordingly, if a projection (clip portion) is previously formed on the cover, the roll can easily bite the clip portion. As a result, the cover is reliably entangled and is peeled from the core through the rotation of the roll. Moreover, the rear end of the roll has a large diameter and the rotary shaft of the roll can also have a large diameter. Therefore, it is also possible to support and rotate the roll like a cantilever. Furthermore, when the clip portion is once bitten into the nip, the cover is pulled obliquely downward. Consequently, the ball is moved toward the large diameter side over the roll. Thus, the cover can be peeled efficiently.
In order to achieve the object, another invention provides a cover peeling machine in which a pair of rolls provided close to each other are mutually rotated reversely to entangle a cover of a golf ball and to peel the cover from a core,
wherein the roll is a tapered roll including a surfacing region having a surface subjected to a non-slip treatment and a tip of the surfacing region has a diameter of 15 mm or less.
Also in the cover peeling machine, the tip of the tapered roll has a small diameter. Therefore, the clip portion is easily bitten between the rolls. Moreover, the clip portion is bitten more reliably by the surfacing region (that is, the portion having the surface subjected to the non-slip treatment). If the tip of the surfacing region has a diameter of 15 mm or less, the clip portion can be bitten by the portion which has the non-slip treatment and in which the distance between the lower end of the ball and the nip is reduced.
The non-slip treatment implies a treatment in which concavo-convex portions are formed on the surface of the roll and to which grooving and knurling correspond. In the grooving, a large number of grooves are extended at regular intervals in an almost longitudinal direction of the roll. It is preferable that the space between the adjacent grooves should have a roll center angle of 6 degrees to 15 degrees.
It is preferable that the space between the rolls should be 0.05 to 0.9 time as great as a thickness of the cover. Consequently, an extremely great load (rolling load) is not applied to the roll, and furthermore, the roll and the cover can be prevented from slipping.
A method of manufacturing a golf ball according to the present invention comprises the step of coating another core with a resin composition containing, as a raw material, the cover obtained by the cover peeling machine described above. In this case, the core may be manufactured newly or may be collected from the used balls. The manufacturing method is excellent in resource saving and environmental maintenance.
Another method of manufacturing a golf ball according to the present invention comprises the step of coating, with a resin composition, the core from which the cover is peeled by means of one of the peeling machines described above. In this case, the resin composition for the cover may be manufactured newly or may be manufactured by utilizing a cover collected from the used balls. This manufacturing method is also excellent in resource saving and environmental maintenance.
In order to achieve the object, a further invention provides a method of removing a cover from a core comprising the steps of heating and softening a cover of a golf ball having a core and the cover, forming a clip portion by deforming and protruding a part of the softened cover, and peeling the cover from the core by entangling the formed clip portion in a pair of rolls,
wherein at the softening step, the golf ball is put in a cup including an almost spherical cavity having a greater inside diameter than a diameter of the golf ball and a difference between the inside diameter and the diameter of the golf ball of 0.1 mm to 1.0 mm and is heated by thermal conduction from the cup, thereby softening the cover.
In the removing method, the cup including the cavity having a predetermined inside diameter is used at the softening step. Therefore, the heating can be efficiently carried out over the whole golf ball. Accordingly, the clip portion can be formed easily.
In order to achieve the object, a further invention provides a method of removing a cover from a core comprising the steps of heating and softening a cover of a golf ball having a core and the cover, forming a clip portion by deforming and protruding a part of the softened cover, and peeling the cover from the core by entangling the formed clip portion in a pair of rolls,
wherein at the clip portion forming step, the cover is thinned and a thickness of a minimum thickness portion of the cover after the formation of the clip portion is 0.1 to 0.6 times as great as that of the cover before the formation of the clip portion.
In the removing method, the minimum thickness portion of the cover has a predetermined thickness after the clip portion is formed. Therefore, the cover can be peeled easily.
In order to achieve the object, a further invention provides a method of removing a cover from a core comprising the steps of heating and softening a cover of a golf ball having a core and the cover, forming a clip portion by deforming and protruding a part of the softened cover, and peeling the cover from the core by entangling the formed clip portion in a pair of rolls,
wherein the clip portion formed at the clip portion forming step has a thickness of 2 mm to 6 mm and a width of 2 mm to 12 mm.
In the removing method, it is not very difficult to form the clip portion. In addition, the clip portion thus obtained can easily be bitten between the rolls.
In order to achieve the object, a further invention provides an apparatus for removing a cover of a golf ball from a core, comprising:
a softening station including an upper cup and a lower cup which have almost semispherical cavities, heating means and an ejector;
a clip portion forming station including an upper cup and a lower cup which have almost semispherical cavities, pressurizing means and an ejector;
a peeling station including one of the cover peeling machines described above, and ball pressing means; and
automatic delivery means for holding the golf ball in the softening station and delivering the golf ball to the clip portion forming station, and holding the golf ball in the clip portion forming station and delivering the golf ball to the peeling station.
By the removing apparatus, the cover can be removed from the core efficiently without a manual operation.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the deatiled description and specific examples, while indicating preferred embodiments of the invention, are given by the way of illustration only, since various changes and modifications within the spirit and scope of the invetion will become apparent to those skilled in the art from this detailed description.